Ore concentrator



mm, m mm.

c. M. FULLER El AL &%7

ORE CONCENTRATOR Oiiginal Filed Dec. 25, 1930 s Sheets-Sheet 1 Pm. L

v INVENTOR. Gun/P455 M. FULLER R7390]? Ca DEN/SON A TTORNE YS.

' F@% 2L WW c. M. FULLER ET AL ORE CONCENTRATOR Original Filed Dec. 23, 1930 s Sheets-sheaf 2 INVENTOR' wmmzs M FULLER fiemu/nz 6. DEN/501v ATTORNEYS.

, 193%. c. M. FULLER ET AL ORE CONCENTRATOR Original Filed Dec. 23, 1930 3 Sheets-Sheet 3 INVENTOR. Guam .55 M. FULLE BY fl/Prnuk C. DAN/so Patented Feb. 21, 1939 UNITED STATES PATENT OFFICE ORE GONGENTRATOR Charles M. Fuller, Los Angeles, Calif., and Arthur G. Denison, Yearington, Nev., assignors to E. D. Wilkinson, Stockton, Calif.

11 Claims. (Cl. 209-476) This invention relates to ore concentrators of the type wherein recurring blasts of air are maintained through a cloth membrane against which the rifiles are seated, and the objects of the invention are to provide improvements in this class of apparatus whereby its effectiveness is greatly increased, especially in its ability to save the finer dust-like particles of gold and other heavy metals. This application is the same as abandoned appli- 10 cation, Ser. No. 504,291, filed December 23, 1930.

In the drawings accompanying this application Fig. 1 is a plan view of our concentrator with portions broken away exposing the screen, frame, and angular riflle supports.

5 Fig. 2 is a side view of Fig. 1 with the lower portion of the bellows casing broken away as from line 2-2 thereof.

Fig. 3 is an end view of Fig. 2 as seen from the line 3-3 thereof.

20 Fig. 4 is an enlarged cross section of one of the riffles and associated parts as seen from the line 4-4 of Fig. 1.

Fig. 5 is a side view of two of our concentrators as erected in a battery for use and shows the simultaneous control of the shutters, working angles, etc., of all of the units in the battery while running.

In further detail the apparatus comprises a rectangular frame I preferably of wood and over the upper side of which is tightly stretched a layer of fine metal screening 2, and on top of this a layer of closely woven cloth 3, all secured in place as by nails 4 to the outer edges of the frame.

The wooden frame is reinforced with an angle 3r iron frame extending across the open space of WhlCh 1s a series of angularly arranged channels 6 formed of sheet metal as best shown in Fig. 4 and with the upwardly opening channel fitted with a thick strip of good hard felt I which projects slightly above the channel. These channels are Welded at their ends to the frame 5 and they slant from the center outwardly toward the discharge end of the concentrator and where they join in the center they are connected by a metal 45 braclzf 8 welded at the joints to form a rigid networ Frame 5 is firmly bolted to the upper flange 9 of a sheet metal bellows casing 9 and between which flange and the frame is a felt gasket I l t make the joint air-tight.

The bellows casing has flat sides and arcuate ends curved from. the axis of a transversely extending rock shaft l2 on which is secured a hub l3 carrying two vanes l4 extending at an angle to one another as shown in Fig. 2 and the ends and edges of which vanes are made air-tight by heavy felt or other resilient pads l5, while a central vertical wall l6 above the shaft divides the rifiles into an upper and a lower set each acted upon by one of the bellows vanes, a soft felt joint I! being 5 placed over the vanes above the shaft to insure separate action of the'two sides of the bellows.

Each bellows vane is provided with a springcontrolled relief valve l8 which opens upwardly upon the down stroke of the vane to permit the 10 compartment above to fill with air and closes upon the upward stroke so that the air will be forced through the cloth. The rocking of the vanes is accomplished through means of a connecting rod IS, the upper end of which may be pivotally connected to any of several holes in a connecting plate 29, and the lower end to any of several holes in a rocker arm 2| extending downwardly from. a shaft 22 which may be fitted withany number of such rocker arms for operating a battery of the concentrators and which shaft is itself rocked by means of a drive crank connection 23 extending from a rocker arm 2| at the remote end of the shaft to a revolving crank 24 driven by a pulley 25 and belt 26. or any other form of drive.

Above screen frame l-5 is a rifile frame 21 across which is secured a plurality of sheet metal riifles 28. These riflies are angularly arranged to match the arrangement of channels 6 and are of narrower width where they contact the cloth 3 so that upon seouringthe frame down solidly upon frame I by means of bolts 29 the cloth and screen will be forced slightly into the channels to form a, series of transversely extending air-tight joints with the riffles above. 3

These rifiles are hollow as best shown in Fig. 4, beveled from the upper edges in a direction extending forwardly of the apparatus toward the cloth and perforated with fine holes 3|] on the working face, all in a manner that any fine par- 40 ticles running down the concentrator over the riffles will be in a measure trapped under the slanting edges of the riffles and if fine enough will pass through the perforations to the interior of the riifles for discharge through their open ends to the channel-like margins 3| running along the two opposite edges of frame 21, for discharge of values, and formed by side plates 3| The triangular open ends of the hollow riflies discharge through openings 32 in the vertical sides of frame 21 and which openings are large enough to also discharge certain material from the upper perforated face of each hollow riflle, such for instanceas the larger particles of gold and other precious metals too large to bounce through the perforations of the riifles upon operation of the apparatus.

Above the hollow rifiles and extending in opposite angularity is a plurality of sheet metal angle bars 33 or converging blades, soldered or welded at both ends to frame 21 and to the upper walls of the hollow rifiles where they cross the same. A longitudinally extending central brace 34 stiflens the riffie assembly in the center.

The size of the free openings for discharge of material from the upper face of and at the ends of the riflles is controlled by sliding gates or plates 35 slidably mounted at 36, 31 to the sides 2'! of the upper or rifile frame and which slides are notched out at a plurality of points as at 38 corresponding to the ends of the riflles so that upon sliding the plates the effective discharge opening above each riflle will be changed, but without altering the discharge passage from the hollow interior of the rifiles.

There is a slide plate or gate 35 on both sides of each rifile frame or unit, and when installed in a battery of units the slides may be simultaneously operated, even while all are in motion, through means of arevolvable shaft 36' extending across and supported upon the discharge end of frame 21 and connected by linkage 31, 38 with one end of the slides, so that upon turning a hand lever 39 at the end of the shaft and locking same in the notches of a quadrant 40 any adjustment of the slides may be secured.

When mounted, the bellows housings or casing 9 are pivotally supported at 4| on-cross member 42 of a rigid frame 43 and each housing is adjustably linked as at 44 to a rock shaft 45 which may be locked in various positions by a quadrant lever 46. The rock shaft is thus linked to any number of bellows housing and consequently the riflle frames above may beset at any working angle desired or altered while the battery of concentrators are running.

Fig. indicates two rows of the concentrators, the bellows of which are operated from a common rock shaft 22, and the gold bearing sand is fed from a chute or suitable conveyor trough 41 to the upper receiving distributing plate 48 over the rifflesand converging blades for discharge of the separated values from side channels 3| to suitable chutes 48,-Whilethe stripped sand is converged centrally by blades 33 and discharged over tailings plate 49 to discharge chute 50..

During operation, the.riflie frames are intermittently vibrated by means of spring hammers 5| which are raised by. revolving cams 52 on a shaft 53. The hammers are pivoted at 54 to the frame 43 and strike an anvil Even the upper end of each riffie frame through the force of a spring 56 upon falling off of cam 52'. Cam shaft 53 is driven by any suitable source of power by means of a belt 51.

In operation, a steady stream of sand is run over the .concentrators from the chute or feeder 4! and the bellows and vibrating hammers started. The amount of air at each pulsation may be varied by hooking the connecting rods l9 and 23 to the various holes in cranks 2 I, 2| and the relation of the air pulsations. in the lower half of the concentrator relative tothe upper half may be varied by shifting the connecting rod IS in the Various holes in plate 20.. The proper adjustment of the air pressure should be suchas to raise all the lighter particles over the rifiles but not sufficient to throw over the heavier metals contained. The finer values will find their way through the perforations of the faces of the hollow rifiles for free travel through them-to run outat the ends to the channel-like margins 3| of the cloth covered frame for final discharge below, the margins 3| being vibrated by the air pulsations causing gold to readily gravitate.

The larger particles not thrown through the perforations work along the face of the hollow rifiles. The under-cut form of the riffle face as best shown in Fig. 4 insures that the values will not be thrown above the riiiies by the air pulsations. Also it is important to note that along the upper side of each perforated riffle is a ledge designated 53 in Fig. 4 formed by the projecting felt and channel 6 below, and which creates an eddy in the air currents forming a dead air space or pocket into which values will gather and drift. This feature is especially claimed herein.

An important feature of the construction is the separable rifiie frame with the riflies fitting over the felt channels 3 below so as to tension the cloth tightly against the lower edge of each rifiie.

The action of the outer blades 33 is to distribute the outer layer of descending material in reverse direction from the riffie action so as to get a constant working back and forth of the material, and with the stripped material finally discharged centrally over plate Q9.

Having thus described our invention We claim:

1. In an ore concentrator, an inclined sheet of tensioned fabric arranged and adapted to support value bearing ore for passage in a general downward direction thereover, a plurality of hollow riflle bars thereon each extending across the path of travel of the ore, said riffle bars being open on their working faces respectively for admission of values, and open at their ends for discharge of the same.

2. In an ore concentration, an inclined sheet of tensioned fabric arranged and adapted to support value bearing ore for passage in a general downward direction thereover, a plurality of hollow riffle bars thereon each extending across the path of travel of the ore, said rifile bars being open on their working faces respectively for admission of values, and open at their outer ends for discharge of the same, and a connecting passageway for the values discharged by all of the riffie bars.

3. In a concentrator of the character described, an inclined sheet of tensioned fabric arranged and adapted to support value bearing ore for passage in a ganeral downward direction thereover, a frame on the sheet of fabric provided with a plurality of rifiie bars extending angularly across the path of travel of the ore, and a plurality of distributor bars on top of said rilile bars arranged to cross the same, said rifile bars being hollow and the sides thereof opposing the passage of the ore being perforated.

4. In an ore concentrator having a riflie frame which includes a sheet of tensioned fabric disposed in a single plane and rifiie bars seated thereon, a bellows casing below and supporting said frame, said casing having flat sides and arouate opposite ends formed about a common axis extending transversely of the casing, a pair of bellows vanes Within the casing, means pivotally mounting the vanes on said axis for reciprocation, said vanes being disposed with their outer ends respectively in sliding sealed contact with the arcuate opposite ends of the casing, means for altering the relative stroke of said vanes, and means dividng the bellows into separate compartments.

5. In an ore concentrator as defined in claim 4,

means pivotally mounting the bellows casing in- 7 cluding the riffle frame thereon for adjustment of its working angle.

6. In an ore concentrator, a rifile frame including hollow riffles, a tensioned porous membrane against which the rifiles seat, means for causing pulsations of air through the membrane, a ledge at the front of each riflie causing a dead air space or pocket adjacent the working face of the rifiie, and the working face of the riffle being perforated.

7. In an ore concentrator, a flat tensioned sheet of fabric arranged and adapted to support value bearing ore for movement thereover along apath of travel, a plurality of rillie bars on the sheet disposed obliquely across said path of travel whereby the values are forced along one of the lateral sides of each of said rifile bars toward an. outer end thereof, side plates contacting the outer ends of the bars and a slidably mounted plate arranged adjacent the ends of the rifile bars, said plate being notched to provide a series of adjustable discharge openings for material leaving the ends of said rilfle bars and said riflle bars being hollow and perforated on the lateral side against which the values are forced.

8. In an ore concentrator, a table for support ing value bearing ore thereon including a top formed of a tensioned porous membrane, means for causing pulsations of air through the membrane in an upward direction, a plurality of riifles above the table and supported thereon, said table being inclined for passing the ore thereover from the elevated toward the lower end, said rifiles extending in a direction transversely of the path of travel of the ore whereby the side of each rifile adjacent the elevated end provides a working face for engaging the ore as it passes over the table, a projecting ledge adjacent the working face of each riflle below the porous membrane and in engagement therewith for forming a dead air space along the working face for collection of values along the working face and over the ledge out of the currents of pulsating air, and means for removing the Values directly from the dead air space at a plurality of points along the rifiles: and out of the influence of the ore on the table and the upper surface of said membrane being unobstructed and uncovered over the area of the dead air space adjacent each riflie for free flow of values on the membrane into said dead air space.

9. In an ore concentrator of the character described, an inclined table top providing an elevated and a lowered end and a plurality of spaced elongated riifles adjacent the upper surface of the top extending across the table from side to side thereof and projecting thereabove, said top being formed of porous fabric extending between adjacent riiiles, means for causing pulsations of air through the fabric in an upward direction, the sides of said riffles facing the elevated end of the table providing working faces for engaging ore and values passing over the table from the elevated to the lowered end, said riffles each being formed along the edge thereof adjacent the table to permit values to pass from the side adjacent "the working face thereof and away from the table top at a point below the upper edge of the riffle and the riflles each also being formed to provide a covered passageway extending longitudinally thereof along said opposite side for receiving the values passing the rifile below the upper edge thereof whereby the values passing to the covered passageway will be removed from the influence of ore passing over the upper edges of the riflies and above the covered passageway.

10. In an ore concentrator of the character described, an inclined table top providing an elevated and a lowered end and a plurality of spaced elongated riifles adjacent the upper surface of the top extending across the table from side to side thereof and projecting thereabove, said top being formed of porous fabric extending between adjacent riifles, means for causing pulsations of air through the fabric in an upward direction, the sides of said riffles facing the elevated end of the table providing working faces for engaging ore and values passing over the table from the elevated to the lowered end, said rifiles each being formed along the edge thereof adjacent the table to permit values to pass from the side adjacent the working face thereof and away from the table top at a point below the upper edge of the rifile and the rifiles each also being formed to provide a covered passageway extending longitudinally thereof along said opposite side for receiving the values passing the riffle below the upper edge thereof whereby the values passing to the covered passageway will be removed from the influence of ore passing over the upper edges of the riflies and above the covered passageway, the working face of each rifile overhanging the fabric of the table top adjacent thereto, and means forming an imperforate ledge projecting from the lower edge of each riffle toward the upper end of the table thereby forming a substantially dead air pocket adjacent the working face of each riffle along the working face whereby values adjacent the working face of each riifle will be substantially out of the influence of the air pulsations.

11. In an ore concentrator, a table for supporting the ore and values thereon, including a top formed of a tensioned porous membrane, means a ore and values passing over the table, a covered passageway extending longitudinally of each riffle along the side opposite the working face thereof and communicating with the space over and adjacent the upper surface of the table next to said working facefor permitting passage of heavier values from along the working face of each riflie to within the covered passageway whereby the values adjacent the upper surface of the table will be removed from the influence of the ore passing over the riffles and above the covered passageway toward the lower end of the table, and means forming an imperforate ledge projecting from the portion of each riiile adjacent the upper surface of the table toward the upper end of the table thereby forming a space over the said ledge and along the working face of each riflle in which ore on the ledge is substantially out of the influence of the air pulsations.

CHARLES M. FULLER. ARTHUR C. DENISON. 

